 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.ide.registry;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.ui.internal.ide.IDEWorkbenchPlugin;
 import org.eclipse.ui.plugin.AbstractUIPlugin;

 /**
  * A strategy to project nature image extensions from the registry.
  */
 public class ProjectImageRegistryReader extends IDERegistryReader {
     private static final String TAG_IMAGE = "image";//$NON-NLS-1$

     private static final String ATT_ID = "id";//$NON-NLS-1$

     private static final String ATT_NATURE_ID = "natureId";//$NON-NLS-1$

     private static final String ATT_ICON = "icon";//$NON-NLS-1$

     private ProjectImageRegistry registry;

     /**
      * Reads the contents of the given element
      */
     protected boolean readElement(IConfigurationElement element) {
         if (!element.getName().equals(TAG_IMAGE)) {
             return false;
         }

         String id = element.getAttribute(ATT_ID);
         if (id == null) {
             logMissingAttribute(element, ATT_ID);
             return true;
         }

         String natureId = element.getAttribute(ATT_NATURE_ID);
         if (natureId == null) {
             logMissingAttribute(element, ATT_NATURE_ID);
             return true;
         }

         String icon = element.getAttribute(ATT_ICON);
         if (icon == null) {
             logMissingAttribute(element, ATT_ICON);
             return true;
         }
         String extendingPluginId = element.getNamespace();
         ImageDescriptor image = AbstractUIPlugin.imageDescriptorFromPlugin(
                 extendingPluginId, icon);

         if (image != null) {
             registry.setNatureImage(natureId, image);
         }

         return true;
     }

     /**
      * Read the project nature images within a registry.
      */
     public void readProjectNatureImages(IExtensionRegistry in,
             ProjectImageRegistry out) {
         registry = out;
         readRegistry(in, IDEWorkbenchPlugin.IDE_WORKBENCH,
                 IDEWorkbenchPlugin.PL_PROJECT_NATURE_IMAGES);
     }
 }

